The invention relates generally to a controller that automatically maintains a level of water in a swimming pool. More particularly, the invention relates to a controller for a water level system for a swimming pool that monitors water level and automatically replenishes or expels water to maintain the desired level of water in the pool.
Backyard pools mean loads of fun, but also mean loads of maintenance and diligence to maintain the cleanliness of the water. The pool owner must use both chemical and mechanical means to keep the water safe from organisms that cause a panoply of illnesses, some serious. Debris, stray animals, and normal use all contribute to the bioburden in the water. Pools are treated chemically to prevent bacterial and fungal growth. Mechanical means of cleaning the pool include a pool pump, a filter and a skimmer. The skimmer is typically located at the water line of a swimming pool. It filters out the floating debris from the pool before it sinks to the bottom of the pool. This prevents the debris from being pulled into and clogging the filter. The skimmer is in the upper part of the side of both in-ground and above-ground pools.
For the skimmer to work efficiently, the water level must be at the level of the skimmer inlet. The skimmer inlet is around one-half foot in height, but can vary as much as from three to nine inches. If the water level is below the skimmer, the skimmer cannot function because the floating debris is below the inlet. Additionally, the pump runs dry, sucks air instead of water, causing the pump to overheat and potentially burn out. If the water level is above the skimmer, debris floating on the water is above the skimmer and the skimmer cannot capture it. The pool owner wants the water level to be within the range of the opening of the skimmer inlet, otherwise debris will clog the pump and the sudden increase in bioburden from debris possibly could overwhelm the chemical system.
Pool water levels change generally due to natural causes. Evaporation, particularly from solar heating, causes the water level to decrease. Many have proposed various solutions to this problem. Most of these solutions are difficult to install and are permanently connected to the pool. One solution has been proposed that is as a separate permanent float chamber external to the pool with a floating sensor that opens a valve to recirculate water to maintain water level and in one example, uses a ball-cock valve to add water. Others have proposed a single cantilevered sensor connected to a hose with a valve to add water. A wireless system employing a pair of capacitive electrodes that transmit information about liquid level to receiver controlling pumps has been also proposed, as well as a flow controller with two micro-switches inside a immersible chamber inside a second chamber.
As electronic systems become more complex, one has proposed delay and monitoring circuitry to adjust levels by signally when to add and when to stop adding water. Others use a transmitter and a microprocessor sensor to transmit radio signals to open valve to add water. The system turns on an overfill counter to prevent the water level from exceeding the desired level. Others have invented systems to prevent false signals to add water by detecting small variations in the water level caused by waves created by a child entering the pool or has delay circuits so that normal motion does create a false signal to add water.
All of these units are for adding water to make up for water lost in evaporation. However, occasionally a pool becomes overfilled because of a heavy rainstorm that dumps inches of water in a short time at a rate up to two inches per hour. Just as a skimmer is ineffective when the water level is below the skimmer, so too it is ineffective when the water level is above. Ironically, this is when a skimmer is especially needed, because storms often cause a large amount of debris to be scattered that ends up in the pool. Even if the pool owner has a reversible pump to remove the excess water, it is generally unsafe to go outside in a heavy storm to manually turn it on, especially if there is lightning activity. None have proposed a solution for reducing the water level in this or similar situations.
While these units may be suitable for the particular purpose employed, or for general use, they would not be as suitable for the purposes of the present invention as disclosed hereafter.